Spark-gap attachment for spark-plugs



' H. C. POGUE. SPARK GAP ATTACHMENT FOR SPARK PLUGS. APPLICATION FILED FEB. 19, 1919.

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Patented Jan. 27, 1920.

which a fiange on the 1s swaged l/O-\g1\G apermanent gas tight UNITED HOMER C. POGUE, OF CHICAGO, ILLINOIS.

SPARK-GAP ATTACHMENT FOR SPARK-PLUGS.

Application filed February 19, 1919.

To all whom it may concern:

Be it known that I, HOMER C. POGUE, a citizen of the United States of America, residing at Chicago, in the county of Cook and State o-fIllinois. have invented certain new and useful Improvements in Spark-Gap Attaclnnents for Spark-Plugs, of which the following is a specification.

This invention relates to a spark gap attachment for the spark plugs of explosive gas engines, and its chief object is to design an attachment which is so simple and compact and rugged in its structure that it will stand up under the severe operating conditions to which it is normally subjected. It is, moreover, my intention to design a spark gap attachment that can be readily attached without labor or eXpense;'that is proof against mal-adjustment; and that can be so inexpensively manufactured that it can be put on the market at a small cost.

With these objects in view, I first contemplate providing my attachment with a threaded base adapted to be screwed onto the exposed threaded end of the spark plugs electrode and providing the spaced terminal to give the spark gap in the attachment by the use preferably of a headed screw which is screwed through a recessed fiber nut about base of the attachment joint. The screw head fits intothe fiber nut recess and when screwed home gives the normal spark gap between it and the electrode, and the terminal nuts on said screw holdit locked in position in the fiber nut.

My invention also comprises the novel details of construction and arrangements of parts, which are illustrated in their preferred embodiment only in the accompanying drawings which form a part of this specification, and in which Figure 1 illustrates a standard spark plug in elevation with my attachment mounted thereon and shown in Vertical cross section. Fig. 2 is a detail View of the metallic base member of the attachment; and

Fig. 3 is a perspective view of the recessed fiber nut forming the upper member of the attachment.

Fig. 4 illustrates a modification of my invention in which a porcelain nut 5 is cemented in the metallic base member of the attachment.

Similar reference numerals refer to similar parts throughout the drawings.

Specification of Letters Patent.

Patented Jan. 27, 1920.

Serial No. 277,970,

As illustrated, the spark plug 1 is representative of any standard type of spark plug. The plug has a threaded stem 2 forming an electrode and projecting above its upper end for the reception of the terminal nuts that bind the wire lead thereto. T he base member 3 of my invention is screwed onto the electrode 2 and is preferably formed by a brass socket member having a deep cylindrical recess in its upper face terminating at a flat bottom 4 which preferably lies flush with the top of the electrode 2 when the socket member is screwed home thereon. The upper edge of the socket member is thin so that it can be readily swaged into a circumferential groove 5 surrounding the middle portion of a threaded fiber nut (3. This nut is provided in its underface with a countersunk seat or socket 7 slightly greater in depth than the thickness of the fillister head 8 on a machine screw 9 which is screwed through the nut with its upper end projecting so as to receive a brass nut 10 forming one of the terminal nuts for the electric wire.

The attachmentis assembled in the following manner :-The machine screw 9 is screwed upwardly through the fiber nut until its head occupies the predetermined distance from the bottom of the fiber nut and generally this distance is obtained when the head is screwed home against the end wall of the socket 7 The nut 10 is then run on and forms both a lock nut to hold the screw in position in the fiber nut and one of the terminal nuts. The fiber nut is then inserted into the socket in the base member and the top edge of the latter is crimped or swaged into the circumferential groove surrounding the fiber nut, thus permanently jointing the top and bottom members of the attachment in position with the head of the machine screw standing in line with and properly spaced from the electrode 2 to produce the requisite spark gap.

Having connected the electric wire 12 by a nut 10 and binding nut 11 to the machine screw 9 and screwed the base 1 onto the electrode 2 of the spark plug, the attachment is ready for service and as the sparking circuit is closed the spark will jump from the fillister head of the machine screw 9 to the electrode 2 through an inclosed chamber to which the gasolene fumes and oil cannot gain access, due to the fact that the swaged joint between the top and bottom members of the attachment is a permanent leak tight joint. Theattachment will be rigid with the spark plug and is of short and compact design so that it will project only a fraction of an inch above the electrode 2, thus requiring no extra head room and offering no obstruction to work on the motor.

This invention is not intended to be restricted in scope to the specific embodiments shown, but contemplates such modifications as come within the spirit and scope of the claims.

In Fig. at a porcelain insulating nut 13 is used similar to nut 6 except that it is pro- Vided with a groove 14 which receives the cement that secures it against displacement in the metallic base member 3. A fiber nut 15 is employed under the nut 10 in this construction and the operation is the same as that already described.

VVhatI claim as new and desire to secure by Letters Patent, is

l. A spark gap attachment for spark plugs having an exposed threaded electrode comprising, in combination, a base member with a threaded opening by whichit is adapted to be screwed on the exposed threaded elec trode of the spark plug, an integral insulating top member having a countersunk seat in its undcrface, and'a binding screw passing through said top member with its head housed in said seat, substantially as described.

2. In snark ao attachment for snark L 23 .L L

plugs, a metallic nut having a high circumferential flange adapted to be swaged, a fiber nut having a socketed base adapted to fit snugly into said flange and having a circumferential groove into which the top of said flange is adapted to be swaged to produce a permanent tight joint between said parts, and a screw inserted through said fiber nut and forming an electric terminal adjustable into said socket.

3. In a spark gap attachment for spark plugs, a base formed by a metallic nut havolher of fiber, the fiber nut having ing a thickness substantially corresponding to the exposed threaded length of the spark plug electrode onto which it is adapted to be screwed and having a circumferential integral flange a top member formed by a fiber nut having a countersunk socket in its bottom end. which is adapted to fit snugly into the socket. formed by the flange of the base, said flange being swaged against the top member to form a tight permanent leak proof joint, and a machine screw which is screwed through said top member and has a rounded head seated in said countersunk socket spaced from the base member and exposed to form the binding post, substantially as described.

4. A spark gap attachment for spark plugs comprising two recessed nuts having their recessed ends telescoped and interlocked,

there being alining threaded openings in said nuts, one of which is of insulating material, and a terminal screw which is screwed through said insulator nut with its head in the recess in said nut.

5. A spark gap attachment for s comprising two nuts, one of meta. ind t in its under end, a headed screw screwed upwardly through said fiber nut until its HOMER o. POGUE.

Witness N OMIE WELSH. 

